ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Factors impacting the performance of polymer-based EOR in oil reservoirs

Haider Ali Shakir, Rafal Firas Abdulhameed, Hassanein Abd Ali Hilal, Dheiaa Alfarge, and Ahmed M. Aljarah

Department of Petroleum Engineering, University of Kerbala, Kerbala, Iraq

E-mail: dheiaa@alayen.edu.iq

Received: 16 December 2022  Accepted: 7 April 2023

Abstract:

During the tertiary stage of the oil recovery, adding the polymer components to the injected water would increase the water viscosity resulting in minimizing the mobility ratio between the injected water and the reservoir oil. Therefore, the displacement process becomes more stable and the flood performance would be more efficient. Understanding the main factors controlling the performance of polymer flooding in oil reservoirs should be a priority to optimize the design of polymer injections. In this study, the reported mechanisms of the EOR polymer flooding were comprehensively reviewed. Then, the field cases of polymer projects were gathered from different technical reports as well as different research articles. After that, the approaches of screening criteria for polymer flooding were analyzed. Moreover, several scenarios of reservoir simulation were constructed to investigate where and when the polymer flooding can be successfully applied. From the simulation results of this research, we have found a strong relationship between the optimum polymer viscosity and the oil viscosity according to the author proposed equation, presented as Eq. 3 in this article. According to the obtained equation, when the oil viscosity increases, the polymer viscosity should be increased to obtain better performance for the polymer EOR. This study also found there is a strong connection between the optimum polymer viscosity and the permeability contrast with a significant R² according to the author second proposed equation, presented as Eq. (4) in this article. According to this equation, as far as the permeability contrast increases, we need to increase the polymer viscosity to achieve higher oil recovery factor by injecting polymer. This research shows that the viscosity of the reservoir oil and the permeability contrast are possibly the main factors which control the selection of the polymer viscosity as well as the success or failure of the polymer injection. Based on the findings of this study, we can infer that the polymer viscosity should be carefully selected depending on the oil viscosity and permeability contrast of the candidate reservoir.

Keywords: Polymer flooding; Polymer EOR; Chemical EOR; Oil recovery; Oil reservoir simulation; Improved oil recovery

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-023-02824-1

Chemical Papers 77 (9) 4859–4875 (2023)